Lugged cap forming system

ABSTRACT

Transfer apparatus and method are provided from first ( 15 A, 16 A) to second ( 15 B, 16 B) stations of tooling in a cap ( 11 ) making press. This cap is biased against the first upper tools by a first airstream ( 50 ) introduced under the cap and moves upward with the first station punch ( 45 ). As the punch approaches its top location, a transfer airstream ( 52 ) begins while the first airstream is still on, and moves the cap out through a transfer chute ( 18 ) to the second station. The cap departs the chute and passes detents ( 67 ) on a pair of closed retention fingers ( 60 ) which define an extension of the transfer path from the chute into the open second station tools. A vacuum ( 85 ) applied to a port in the second station punch then holds the cup against the rising upper tools. When the punch clears the closing fingers and approaches its top location, an ejection airstream ( 87 ) commences to propel the finished cup via a discharge chute ( 19 ).

This application is a 371 filing of PCT/US2001/49392, filed Dec. 19,2001, which claims priority from U.S. provisional application Ser. No.60/257,336, filed Dec. 20, 2000.

BACKGROUND OF THE INVENTION

U.S. Pat. Nos. 6,082,944 and 6,015,062, assigned to the assignee of thisapplication, disclose closure constructions for reclosable containers(e.g a can body) wherein a domed container end with a neck portionhaving a pour opening is provided with a reclosable lugged type of cap.That invention provides a unique and versatile container for fluids,particularly for beverages, wherein various standard can bodies areprovided with a two part end including a neck with a pour opening, a lugformation on the neck below the pour opening, a reclosable cap having alug formation which can interlock with the lug formation on the neck andincluding a seal surrounding the pour opening, and thus capable ofmaintaining product under pressure. The two part end is affixed to a canbody by conventional double rolled seam attachment between the bottom ofthe neck and the rim of the can body. However, it is possible to affixthe domed end to a can body without a cap, fill the can though the pouropening, and then apply the cap.

With the possibility of expanded markets for these lugged caps, whichare also useful on various jars and bottles, there is a need for asystem (method and tooling) for producing lugged cap members in a singlemachine, e.g. a reciprocating press fitted with appropriate tooling,which is capable of precise high speed (e.g. in the range of 135 to 150strokes/minute) to achieve acceptable commercial production of the cap.

To develop such production speeds it is desirable to divide theprogressive tooling operations into more than one step, and this in turnrequires a rapid and precise transfer system to move the partiallycompleted caps from a first station to a second station, and preciselyregister the caps in the second station. Prior art transfer systems areknown for moving and registering can end shells, such as in U.S. Pat.Nos. 4,770,022 and 4,895,012, however, the end shells are relativelyflat disc-like objects with a quite small height to diameter ratio,whereas the caps made by the present invention have a substantiallygreater height with respect to their diameter.

Thus, the physical dimensions of the caps involved in this invention arequite different from can shells or easy self-opening can ends. This inturn introduces needs not required or anticipated in shell transfersystems, for example with regard to tipping of the caps during highspeed transfer operations. Also, because of the relatively high presscycling, and need for precision in cap positioning and decelerationimmediately after each transfer to another press station, there is arequirement for precise transfer of each cap from a first press stationthrough high acceleration, very rapid transfer to the next pressstation, and high deceleration to a precisely defined stationarylocation at that next station.

SUMMARY OF THE INVENTION

The present invention provides a transfer apparatus and method for afirst to a second station of progressive tooling in a cap making press.The caps are of a type having substantial height with respect to theirdiameter. Thus a first station punch and die form a cap of generallyinverted cup shape, with an outward curled rim, and a second stationpunch and die form lugs into that rim, requiring just two strokes of thepress to sever a disc from a supply sheet, form it, and discharge acompleted cap.

Thus, in the first station, a cap is formed except for lugs which areadded to the cap in the second station. The formed cap in the firststation, which is in the nature of an inverted cup, has an outward curlformed on its lower edge during the initial up stoke of the press. Thiscup is then biased against the upper forming punch, by a first airstreamintroduced into the cavity within the underside of the cap, and movesupward in contact with the first station punch. As the punch approachesits top dead center location (tooling fully open), a second airstreambegins, before the first station punch is fully raised and while thefirst airstream is still on. This second airstream moves the cap off theraised first station punch, and into and through a transfer chutedirected toward the second station.

At the second station, the cap departs the chute and passes detents on apair of closed retention fingers which, with the tooling open, define anextension of the transfer path from the chute into the open secondstation tools. As the second station tools begin to close and thepartially finished cap is located, the fingers are opened and thetooling operates to form lugs into the cap rim.

As the second station tooling opens, a vacuum applied to a port in thesecond station punch begins to hold the finished cup against that punchtool, and when that punch clears the closing fingers and approaches itstop dead center location, an ejection airstream commences to propel thefinished cup from the tooling via a discharge chute.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom view of a container cap as provided by the invention.

FIG. 2 is a transverse cross-sectional view of a typical completed cap,as shown in FIG. 1.

FIG. 3 is an over all perspective view of the tooling for a four-out capmaking system.

FIG. 4 is an enlarged perspective view, with the die shoe removed,showing details of the tooling, including four first station tools inthe center and four related second station tools outwardly in oppositedirections of the first stations.

FIG. 5 is a further enlarged perspective view showing details of onepair of first and second stations of the tooling.

FIG. 6 is a cross-section view of a first station punch or upper tool.

FIG. 7 is a cross-section view of a first station die or lower tool.

FIG. 8 is a cross-section view illustrating the first station punch anddie in closed position, and showing a cap formed except for an outwardcurl at the lower rim of the cap.

FIG. 9 is a cross-section view showing first station and correspondingsecond station tools, a transfer chute between them, the fingers whichprovide an extension of the chute into the second stage tool, and camswhich control movement of the fingers.

FIGS. 10 and 11 are detail views of the top of the second station die,showing the open and closed positions of the fingers.

FIG. 12 is an enlarged cross-section view of the second station tools,and FIG. 12A is a further enlargement of the circled area in the centerof FIG. 12.

FIGS. 13A and 13B1 & 13B2 (three sheets) together are a schematicdiagram of the pneumatic supply & control system of the press andtooling.

FIG. 14 is a flow diagram of the electronic control system for thetooling package.

DESCRIPTION OF PREFERRED EMBODIMENT

The present invention provides a transfer apparatus and method for twostation progressive tooling in a cap making press and system. The capsare of a type having substantial height with respect to their diameter.A typical such cap is shown in FIGS. 1 and 2, which is also shown inFIGS. 2, 4A and 4B of U.S. Pat. No. 6,015,062. The preferably integralcap 11, in the general form of an inverted cup, includes a top panel 12,a peripheral sidewall 13, and a curled rim 14.

In the present drawings, FIGS. 3-12A depict multi-lane progressivetooling comprising four lanes for simultaneously forming four caps 11,each lane comprising pairs of first and second tooling stations 15A,15B, 16A, 16B, 17A,17B, and 18A, 18B, with the first stations 15A-18Aarranged centrally of the tooling (FIGS. 3, 4 & 5) and correspondingsecond stations 16A-16B arranged outward of the first stations towardopposite sides of the upper and lower die plates 20A, 20B which supportthe upper (punch) and lower (die) tooling, and mount between the bed andslide of a reciprocating press (not shown).

Except for their orientation in the overall tooling package, therespective first station and second station tools are alike, and thefollowing detailed description applies to all. Taking stations 15A and15B as examples, each pair of corresponding first and second stationshas an associated transfer chute 19 (FIGS. 4, 5 & 9) between them, andeach second station has a discharge chute 19A, the four of which aredirected out opposite sides of the tooling (FIGS. 3 & 4).

Sheets of metal, with an appropriate pattern of lithographed materialsfor each cap, are fed centrally into the first stations by sheet feedingmechanism of known construction (not shown) which moves the sheets oneat a time in step wise fashion, synchronized to the press strokes, alongthe feed path indicated by arrow IN in FIGS. 3 & 4.

First Station

The first station tools comprise an upper or blank punch tool 45 and acompound lower die. During the initial operation of the first stationtools, with the lithographed patterns aligned with respect to the firststation tools, a blank is cut from the material (typically aluminum orthin cold rolled steel) on the down stroke of the press by blank punch45. On the continuation of the down stroke, the blank punch and lowerdie tool cooperate such that the blank is drawn into a cup shaped cappart 11P (FIG. 8). At the bottom of the stroke the panel shape 12 isformed into the top of cap part lip by the punch 45 and cooperating die46 (FIGS. 6, 7 & 8).

On the up stroke, the lower curl ring 48, which is under springpressure, raises with the blank punch. The bottom edge of the cap part11P is curled outward into the cavity 49 formed by curl ring 48 andblank punch 45, completing a formed cap 11 with an outward curled rim15.

The formed cap in the first station, which is in the nature of aninverted cup, is biased against the upper forming die by a firstairstream introduced through passage 50 (see FIGS. 8 & 9) into the capas the first station tooling opens, and causes the cap to follow upwardagainst the bottom of the punch 45. During the upward travel of the cap,a second airstream is initiated through a nozzle 52 directed across theupper first station tooling toward chute 19, and is at its full powerwhen punch 45 (with a cap 11 held thereto by the upward directed firstairstream) traverses the space between nozzle 52 and the entry to chute19 (see FIG. 9). By the time the first station tooling reaches full openat the top-dead-center of a press stroke, the cap has actually beentransferred into the second station 15B; see Press Rotation timing chartbelow (page 8).

Thus, the first and second airstreams, appropriately switched on andoff, together with the associated chute, constitute a first part of anessentially passive press transfer system.

Second Station

At the second station, a separated pair of fingers 60 reach around thesides of the second station tooling (FIGS. 9, 10 & 11), defining partialsides of a receiving space 62 when the second station tooling is open,and an extension of the transfer chute when closed. The fingers aresupported by pivots 63 inward of their rear ends 61, and are biased intotheir closed position (FIG. 10, forward ends parallel) by springmechanism 64. Each finger has a narrow ledge-like track 65 extendingpart way along its forward upper edge (FIGS. 10-12), facing each otherand ending in a curved section 66. Extending horizontally inward overtracks 65 are spring-loaded ball detents 67 which, together with thecurved track sections 66, define the termination of the transfer pathfor the incoming caps.

A cap propelled from the first station traverses the adjacent transferchute 19 and enters receiving space 62, passing across ball detents 67and resting against the curved track sections 66 (see FIG. 11). Thefingers and their operating mechanism form the remainder of the uniquetransfer system.

As the tooling proceeds to close during the beginning of a next stroke,fingers 60 are swung outward by descending cams 48 pressing againstfollowers 49 on the rear ends 61 of the fingers to move the followers 49inward and the forward section of the fingers outward (FIGS. 10 & 12)before the second station tools close. The elongated cams 48 are mountedon the upper (die) tooling base (FIG. 12), and this action centers a cap(FIG. 11) and then opens the fingers associated with the second stationtooling, before that tooling closes to form lugs on rim 15 of a cap 11.This closing action of fingers 60 is momentary, and they are then openedsubstantially before the second station tooling closes; see PressRotation timing chart below.

In the second station 15B in the press, the tooling includes an upperpunch 70 and a lower die 72. The punch tool 70 includes an annular knockout ring 71 with an inner shape conforming to a cap exterior, and aheaded knock out pin 73 which is spring loaded toward a position flushwith the lower edge of ring 71 (FIGS. 12 & 12A) when the tooling isopened. In the lower die 72 there is a vertically extending tapered cam74 mounted onto a base plate 75 and surrounded by a plurality of diepins 76 also mounted onto plate 75. The cam 74 and pins 76 projectthrough a vertically movable, upwardly biased ring 78 which contains aplurality of lug forming dies 80, equal in number to pins 76 and movablelaterally outward through forces from cam 74 as it is made to enter ring78. The top of ring 78 has an upper surface 82 contoured to fit within acap 11.

Thus, when the second station tooling closes a cap is positioned withthe curled rim 15 between the upper ends of pins 76 and the radiallyoutward moving forming dies 80, to for the predetermined number of lugsin the rim (FIG. 1). Then, the completed cap is held to the knockout pinby means of a vacuum created in passage 85 though the head of that pin73, such that the cap is carried upward past an air nozzle 87 directedacross the path of the rising upper tool toward an associated dischargechute 19A. The vacuum is created by air flow through a small venturi(not shown) so the vacuum is relieved immediately upon cessation of airflow through that venturi. A discharge air stream is started from nozzle87 and moves the cap from the upper knock out ring and pin, into andthrough the associated discharge chute 19.

Press Rotation Relation to Tooling Function

1st Station

-   -   0° Top of the Stroke; Top Dead Center    -   140° Material is Blanked    -   180° Form & draw complete; Bottom Dead Center; Cap Overall        Height ˜0.810 inch    -   190° Cap Curl complete; Overall Height is ˜0.625 inch    -   190° 1st Air turned on; Blows cap against punch tool    -   220° Blank punch exits Die tool, cap against its face    -   230° 2nd Transfer Air on; Blows cap into transfer chute    -   330° 1st Cap arrives into catch fingers at 2nd Station.

2nd Station

-   -   0° Top of a stroke; Top Dead Center    -   60° Upper vacuum is turned on    -   136° Catch fingers start open, upper vacuum holds 1st cap        against upper knockout and tools close    -   180° Lugs formed in 1st cap; Bottom Dead Center    -   181° 1st cap (completed) and tools move up together    -   224° Catch fingers close completely after tooling passes    -   270° Upper vacuum to knockout turned off    -   280° Discharge air valve to nozzle is turned on    -   290° Knock out air to nozzle 87 is turned on    -   330° 2nd Cap arrives into catch fingers    -   336° 1st Cap actually moves to discharge position    -   335° Vacuum actually turns off on Cap #1    -   350° 1st Cap actually leaves press via chute 19

FIGS. 13A and 13B comprise a pneumatic diagram for the pneumatic portionof the press control. A “shop air” source of compressed air is suppliedto the various electrically controlled valves (which are all labeled) todirect air under pressure to the above mentioned parts of the tooling,under management control of the electronics control (FIG. 14) of thesystem. The details of such controls are apparent to persons skilled inthis art from these diagrams

FIG. 14 is a block diagram of electrical/electronics controls for thesystem, which selectively turn on and off the compressed air to thenozzles providing lift or “blow up” air to hold the cap part against therising upper tools in the first station, and providing a transfer airstream to quickly move a cap part into a transfer chute 19. The third(upper) control provides timed discharge airstreams through nozzles 87to move the finished caps into the discharge chutes 19A. A pulsegenerator PG is driven by the press crankshaft (not shown) in typicalfashion to generate a train of pulses related to the angular position ofthe crankshaft as it rotates, and these pulses are directed to thesystem PLC (Programmable Logic Controller). Since the diagram is dividedinto three functions which occur during a press cycle, the controllerPLC is shown in each of the three diagram parts, but in fact one PLC isemployed in the control system.

While the method herein described, and the form of apparatus forcarrying this method into effect, constitute preferred embodiments ofthis invention, it is to be understood that the invention is not limitedto this precise method and form of apparatus, and that changes may bemade in either without departing from the scope of the invention, whichis defined in the appended claims.

1. In a cap making system for forming integral reclosable container capsfrom sheet metal in a reciprocating press, said caps having asubstantial height with respect to their diameter for fitting around andover a container neck portion with a pour opening, said systemcomprising a first station and a second station mounted in the press ata predetermined distance apart, said first station including firststation tools comprising a blank punch tool and a cooperating compounddie tool mounted in a reciprocating press for cyclic movement between anopen position in which said tools are separated and a closed position inwhich said tools are closely spaced to form a cap from a metal blank,said first station tools operating to separate a blank from a supply ofthin sheet metal during initial closing motion of said first stationtools and then to draw the blank into a cup shaped part having a toppanel and a cylindrical side wall extending from said top panel, andthen to form an outward curled rim on the open lower edge of the cupshaped part, said second station being aligned with and spaced from saidfirst station, said second station including second station toolsmounted in the press laterally of said first station tools for receivingparts from said first station tools and performing further operationsthereon, a chute extending between said first station and second stationtools at their open position and receiving parts in transfer from saidfirst station tools toward the second station tools, said chuteterminating adjacent the interface of said second station tools at theirclosed position, a set of spaced apart guide fingers shaped to form acontinuation of said chute, said fingers being supported on oppositesides of the second station tools for movement toward and away from saidsecond station tools, means for moving said fingers apart during closingof the second station tools and for moving said fingers into anextension of said chute when the second station tools are open, meansprojecting a first air stream into the interior of a cup shaped part insaid first station tools to hold the top panel of said cup shaped partagainst said blank punch tool during separating motion of said firststation tools upon forming a part, means projecting a second air streamacross said blank punch tool at its open position and into said chute topropel cap parts into said second station tools, and control meanscoordinated with the operation of the press and connected to said meansfor projecting first and second airstreams for switching on said firstand second air stream projecting means to (a) initiate the first airstream at the beginning of separation of said first station tools andmaintaining the first air stream at least until said first station toolsare fully separated, and (b) initiate the second air stream before saidfirst station tools are fully separated and maintaining the second airstream sufficiently to propel the part through said chute.
 2. A systemas defined in claim 1, wherein said fingers have complementary tracksformed thereon to receive and guide a part exiting said cute, saidtracks having inwardly curved end sections positioned to align with thecenter of the second station tools to form a termination of the path ofa cap part entering the second station tools, and cam means operated bythe press in coordination with opening and closing of the second sectiontools to move the fingers apart when the tools are closing and to closethe fingers into a chute extension when the tools are opening.
 3. Asystem as defined in claim 2, wherein said finger tracks include detentsspaced from said inwardly curved end sections to define a centeredposition of the part along said curved end sections.
 4. A system forforming reclosable container caps having a cylindrical body ofsubstantial height with respect to its diameter and an integral upperend panel for fitting around and enclosing a container neck portion witha pour opening against which said end panel can seal; comprising a firststation including first station tools comprising a blank punch tool anda cooperating compound die tool adapted for mounting in a reciprocatingpress for cyclic movement between an open position in which said blankpunch and compound die tools are separated and a closed interfaceposition in which said blank punch and compound die tools are closelyspaced, said blank punch tool and compound die tool being mounted in areciprocating press and cooperating during cyclic operation of the pressto form a cap from a metal blank separated from a supply of thin sheetmetal during closing motion of said tools and then enclosed between saidtools, said blank tool and compound die tool further cooperating duringfurther closing action to draw the blank into a cup shaped part with atop panel and a cylindrical side wall extending from said top panel, andsaid blank tool and compound die tool then forming an outward rolled rimon the side wall, a second station laterally aligned with and spacedfrom said first station, said second station including second stationtools for receiving parts from said first station and performing a lugshaping operation on the rolled rim, the lugs extending inward into therolled rim, a chute extending between said first and second stations atthe open position of said first station tool to guide parts in transferfrom the first station into the second station, said chute terminatingadjacent the interface of the second station tools, a set of spacedapart guide fingers forming a continuation of said chute, said fingersbeing pivotally supported on opposite sides of the second station toolsfor opening and closing motion perpendicular to said second stationtools to clear the closing path of the second station tools to providefor closing of the second station tools with said fingers moved apartand for closing motion of said fingers into an extension of said chutewhen the second station tools are open, said fingers havingcomplementary tracks formed thereon to receive and guide a part exitingsaid chute, said tracks having inwardly curved end sections which alignwith the center of the second station tools, said finger tracks includedetents spaced from said curved end sections to define a centeredposition of incoming parts and to provide a termination of a path of acap part entering the second station tools, cam means operated by thepress in coordination with opening and closing of the second sectiontools to move the fingers apart when the tools are closing and to closethe fingers into a chute extension when the tools are opening, meansprojecting a first air stream into the part to hold the upper end panelagainst said blank punch tool during separating motion of said firststation tools upon forming of a part, means projecting a second airstream across said blank punch tool at its open position and into saidchute so as to propel cap parts into said second station, and controlmeans coordinated with the operation of the press for switching on saidfirst and second air stream projecting means to (a) initiate the firstair stream at the beginning of separation of said first station toolsand maintaining the first air stream at least until said first stationtools are fully separated, and (b) initiate the second air stream beforesaid first station tools are fully separated and maintaining the secondair stream sufficiently to propel the part through said chute, saidcontrol means including an input pulse generator driven in synchronismwith cyclic operation of the press to generate a train of control pulsesrelated to an angular position of a press crankshaft as the presscrankshaft rotates to open and close the tools, whereby initiation andtermination of said air stream projecting means is synchronized withcyclic operation of the tools.
 5. A method for discharging andtransferring a cup shaped object having a substantial height withrespect to its diameter from a work station, said work station havingupper and lower tooling which is opened and closed to form the object,along a transfer path, the open position of the upper tooling defining aready position, comprising the steps of: (a) locating and holding theobject within the work station by directing a first stream ofpressurized gas against the object to cause the object to remain withthe upper tooling upon opening of the tooling whereby the object issupported by the first stream in a ready position against a bottomsurface of the upper tooling; (b) prior to locating the object in saidready position, initiating a second flow of pressurized gas throughorifice means located adjacent to and directed across said readyposition, thereby causing transfer of said object from the work stationwhen the object is released at the ready position; and (c) discontinuingthe second flow of pressurized gas through said orifice means after theobject has exited the open tooling (d) receiving the object in a chuteextending to a second work station which defines the transfer path toadjacent second upper and lower tools of the second work station, (e)directing the object into an extension of the transfer path defined bypivoting fingers located at opposite sides of the second tool, and (f)opening the fingers when the second tools are closing, and closing thefingers when the second tools are opening such as to guide the objectinto a centered position between the second station tools.